package com.common.base.model;

import java.io.Serializable;
import java.util.List;


public class PaginationSupport implements Serializable {
    
    public static int PAGESIZE = 10;
    
    private int pageSize = PAGESIZE;
    
    private List items;//存放查询到的数据列表
    
    private int totalCount;//数据库的总条数
    
    private int[] indexes = new int[0];
    
    private int startIndex = 0;
    
    public PaginationSupport(List items, int totalCount) {
        setPageSize(PAGESIZE);
        setTotalCount(totalCount);
        setItems(items);
        setStartIndex(0);
    }
    
    public PaginationSupport(List items, int totalCount, int startIndex) {
        setPageSize(PAGESIZE);
        setTotalCount(totalCount);
        setItems(items);
        setStartIndex(startIndex);
    }
    
    public PaginationSupport(List items, int totalCount, int pageSize,
            int startIndex)
    {
        setPageSize(pageSize);
        setTotalCount(totalCount);
        setItems(items);
        setStartIndex(startIndex);
    }
    
    public List getItems() {
        return items;
    }
    
    public void setItems(List items) {
        this.items = items;
    }
    
    public int getPageSize() {
        return pageSize;
    }
    
    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }
    
    public int getTotalCount() {
        return totalCount;
    } 
    
    public void setTotalCount(int totalCount) {
        if (totalCount > 0) {
            this.totalCount = totalCount;
            int count = totalCount / pageSize;
            if (totalCount % pageSize > 0)
                count++;
            indexes = new int[count];
            for (int i = 0; i < count; i++) {
                indexes[i] = pageSize * i;
            }
        } else {
            this.totalCount = 0;
        }
    }
    
    public int[] getIndexes() {
        return indexes;
    }
    
    public void setIndexes(int[] indexes) {
        this.indexes = indexes;
    }
    
    public int getStartIndex() {
        return startIndex;
    }
    
    public void setStartIndex(int startIndex) {
        if (totalCount <= 0)
            this.startIndex = 0;
        else if (startIndex >= totalCount)
            this.startIndex = indexes[indexes.length - 1];
        else if (startIndex < 0)
            this.startIndex = 0;
        else {
            this.startIndex = indexes[startIndex / pageSize];
        }
    }
    /**
     * 获得下一页开始的位置
     * @return
     */
    public int getNextIndex() {
        int nextIndex = getStartIndex() + pageSize;
        if (nextIndex >= totalCount)
            return getStartIndex();
        else
            return nextIndex;
    }
    
    /**
     * 获得上一页开始的位置
     * @return
     */
    public int getPreviousIndex() {
        int previousIndex = getStartIndex() - pageSize;
        if (previousIndex < 0)
            return 0;
        else
            return previousIndex;
    }
    
    public int getFirstIndex() {
        return 0;
    }
    
    public int getLastIndex() {
        return pageSize * (indexes.length - 1);
    }  

    /**
     * 总页数
     * @return
     */
    public int getCurrentPage() {
        int currPage=getStartIndex()/pageSize; 
        
        return currPage+1;
    }
    
    /**
     * 
     * @return
     */
    public int getTotalPage() {
        int pageCount=0;
        if (totalCount > 0) { 
            pageCount = totalCount / pageSize;
            if (totalCount % pageSize > 0)
                pageCount++; 
        } 
        return pageCount;
    }
}
